Abstract: A method of infusing and aspirating fluid from the body is provided. The method includes providing a catheter system which includes an inner lumen, the proximal end of which is connected to an infusion mechanism configured to control infusion of a fluid, and an outer lumen, the proximal end of which is connected to an aspiration mechanism configured to control aspiration of fluid from the body. The method also includes activating the infusion mechanism to infuse fluid into the body for a first infusion time period and at a first infusion pressure, disabling the infusion mechanism to stop infusion, and activating the aspiration mechanism to aspirate fluid for a first aspiration time period and at a first aspiration pressure.